Note: Global aerosol index from January 1, 1987 through December 31, 1987 as measured by the Nimbus-7 Total Ozone Mapping Spectrometer (TOMS). Animator: Andy Acuna (Hughes STX). Scientist: Jay Herman (NASA/GSFC), Colin Seftor (NASA/GSFC), N. C. Hsu (University of Maryland Baltimore County), Pawan K. Bhartia (NASA/GSFC). Platforms/Sensors/Data Sets: Nimbus-7/TOMS.